It is known that in radar systems the relative motion between the radar detector and the target is such to introduce degradation effects on the received radar echo signal (or “range profile”). As a matter of fact, it is known that such relative motion introduces blurring—a reduction of the peak level and an increase of the size of the side lobes in the range profile. In particular, this is due to the fact that the relative motion between the radar device and the target introduces both a Doppler displacement and a residual phase modulation into the range profile.
The degradation effects described above have a negative impact—particularly but not exclusively—on the performance or high resolution radar systems, or HRR (High Range Resolution) radar systems, and more in particular the performance of the so-called synthetic band radar systems. In this particular type of systems, obtaining a well focused range profile and maintaining the desirable resolution of the range profile is of vital importance.
Compensation of the abovementioned degradation effects of the range profile by means of processing techniques based on maximizing the contrast measure is known in the prior art. An example of the abovementioned method is for example described in “Focusing of two-dimensional ISAR images by contrast maximization”, by F. Berizzi and G. Corsini, IEEE Transaction on Aerospace and Electronic Systems, 3 Jul. 1996, incorporated herein by reference in its entirety.